The present invention relates generally to a heat dissipation fan, and in particular to a heat dissipation fan having a simple structure and replaceable parts for reducing costs thereof.
Heat dissipation fans are commonly employed to enhance removal of heat generated in computers in order to maintain proper operation of the computers. A side-mount heat dissipation fan comprises a casing having an open top for intake of surrounding air and a side opening in communication with a heat sink to conduct air flow toward and through the heat sink. The casing has a bottom that is closed for supporting a blade assembly comprised of a number of spaced blades for generating air flow during rotation. The blade assembly comprises a central hub or cylinder from which the blades radially and outwardly extend. The central cylinder defines an interior space in which windings for receiving alternate current to induce magnetic field that interacts with magnet to drive the blade assembly are formed.
Conventionally, wires that supply the alternate current to the windings are arranged on the bottom of the casing. Such an arrangement complicates the structure of the fan for a shaft of the blade assembly must be integrated with the bottom of the casing in order to allow the wires to extend therethrough into the blade assembly. The blade assembly is thus not separate from the casing. This means the blade assembly cannot be replaced by a new one if it is damaged or broken or otherwise malfunctioning. Costs of manufacturing and maintenance are thus increased.
The conventional heat dissipation fan comprises a control circuit embodied as a printed circuit board that is mounted to the bottom of the casing for controlling the operation of the blade assembly. This inevitably increases the distance between the bottom of the casing and the fan blades. The increased distance is likely to induce turbulence on the back side of the blades and such turbulence interferes with the air flow generated by the blades. The operation efficiency of the fan is thus reduced.
The present invention is thus aimed to overcome the problems encountered in the conventional heat dissipation fan having electrical wires leading into the fan from a bottom side of the fan.
An object of the present invention is to provide a heat dissipation fan wherein electrical wires that supply alternate current to the fan are arranged on top side of the fan for simplifying the structure of the fan.
Another object of the present invention is to provide a heat dissipation fan wherein replacement of a blade assembly is made possible by removably mounting a shaft of the blade assembly in the casing.
A further object of the present invention is to provide a heat dissipation fan wherein a gap between fan blades and a casing is effectively reduced by arranging electrical wires that supply alternate current into the fan from the top side of the fan.
Yet a further object of the present invention is to provide a low cost heat dissipation fan.
To achieve the above objects, in accordance with the present invention, there is provided a heat dissipation fan having a side mount configuration comprising a casing having a bottom wall and a surrounding side wall extending from the bottom wall to define an open top. The side wall also defines a side opening to guide an air flow toward a heat source. A cross bar is detachably mounted to the open top or is made of resilient material. A shaft is arranged inside the casing and has upper and lower ends removably received in a recess defined in the cross bar and a notch defined in the bottom wall of the casing. A blade assembly comprised of a cylinder and blades extending from the cylinder is rotatably mounted to the shaft. Windings and magnets are arranged inside the cylinder. Electrical wires are electrically connected to the windings via conductive pads formed on the upper end of the shaft or by extending through openings defined in the upper end of the shaft. No control circuit is included in the casing, the distance between the blades and the bottom wall can be substantially reduced and the structure is simplified.